Dialing telephone calls from Sao Tome and Principe to Slovakia
00
▶ 421
▶ city code
▶ local number
Step-by-step
00
▼ This IDD (International Direct Dial) prefix tells the phone system in Sao Tome and Principe that you are dialing an international number.
421
▼ Country code for Slovakia.
city code
▼ local number
Notes
Not sure what time it is on the other end of the line? Look here for Slovakia time, date, and time zone information.
If you are calling from a hotel or office phone system, additional steps may be required.